anv/cmd_buffer: Initalize the clear color struct for CNL+

On CNL+, the clear color struct is composed of RGBA channel values and
fields which are either reserved by the HW or used to control
fast-clears. Currently anv initializes the channel values to zero and
allows the other fields to be undefined.

Satisfy the MBZ field requirements by removing an optimization that
doesn't hold true for CNL+ and pulling in the number of dwords to
initialize from ISL.

Cc: <mesa-stable@lists.freedesktop.org>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
(cherry picked from commit b4198e792c)

src/intel/vulkan/genX_cmd_buffer.c

@@ -762,27 +762,21 @@ init_fast_clear_color(struct anv_cmd_buffer *cmd_buffer,
    set_image_fast_clear_state(cmd_buffer, image, aspect,
                               ANV_FAST_CLEAR_NONE);
 
-   /* The fast clear value dword(s) will be copied into a surface state object.
-    * Ensure that the restrictions of the fields in the dword(s) are followed.
-    *
-    * CCS buffers on SKL+ can have any value set for the clear colors.
-    */
-   if (image->samples == 1 && GEN_GEN >= 9)
-      return;
-
-   /* Other combinations of auxiliary buffers and platforms require specific
-    * values in the clear value dword(s).
+   /* Initialize the struct fields that are accessed for fast-clears so that
+    * the HW restrictions on the field values are satisfied.
     */
    struct anv_address addr =
       anv_image_get_clear_color_addr(cmd_buffer->device, image, aspect);
 
    if (GEN_GEN >= 9) {
-      for (unsigned i = 0; i < 4; i++) {
+      const struct isl_device *isl_dev = &cmd_buffer->device->isl_dev;
+      const unsigned num_dwords = GEN_GEN >= 10 ?
+                                  isl_dev->ss.clear_color_state_size / 4 :
+                                  isl_dev->ss.clear_value_size / 4;
+      for (unsigned i = 0; i < num_dwords; i++) {
          anv_batch_emit(&cmd_buffer->batch, GENX(MI_STORE_DATA_IMM), sdi) {
             sdi.Address = addr;
             sdi.Address.offset += i * 4;
-            /* MCS buffers on SKL+ can only have 1/0 clear colors. */
-            assert(image->samples > 1);
             sdi.ImmediateData = 0;
          }
       }